Recent developments in integrated circuit (IC) design have led to the use of through silicon vias (TSVs) and other structures to form three-dimensional (3D) ICs. While this area of design has increased the density of active circuits, 3D ICs also present challenges that are not encountered, or are less problematic than, in other circuit designs. One challenge is the issue of signal coupling, or interference, between TSVs as they are placed closer and closer together. Not only is the placement of the TSV a factor, but so are the higher and higher frequencies that are being used in circuits.
One previous approach known to the inventors to prevent this interference is the use of guard rings, which results in good shielding across all frequencies. However, not all TSVs can be shielded using this approach, and thus signal integrity and performance issues can remain. The guard ring approach also requires an extra shielding layer for the connection and a relatively large routing area, which adds cost and limits the shielding path (and thus, efficiency).